1. Field of the Invention
Embodiments of the present disclosure generally relate to pressware stacking systems and methods for using same.
2. Description of the Related Art
In a typical pressware product stacking system, a take-away table or conveyor transfers pressware products from a matched metal forming die to a stacking surface. The system stacks the pressware products on top of each other until each stacking surface contains the desired product count. Then the system transfers a completed stack to a second conveyor that leads to packaging equipment. Meanwhile, the system continues to form products at full production speed. To prevent the loss of products during stack transfer, previous systems are configured to slow or stop the take-away table while advancing the completed stack to the second conveyor. Certain systems employ a vertical stop gate system to prevent products from advancing onto the stacking surface.
Problems with both previous designs have resulted in loss and waste of materials and products. For example, when the system slows or stops the take-away table, a pressware product in one or more lanes of a multi-lane conveyor can advance more rapidly on the conveyor than pressware products in adjacent lanes, thus reaching the stacking surface early. Similarly, a pressware product in one or more lanes can lag behind pressware products in adjacent lanes, causing the pressware product to fall into the stacking surface incorrectly or go missing from the stack entirely while the completed stacks of plates are transferred to the second conveyor. This can result in entire system shutdown and/or require human intervention, as well as damage to the products themselves and thus wasted resources. Additionally, stopping or slowing the take-away table can cause improper product placement earlier in the chain when just formed products ejected from the metal forming die fall improperly into the queue of products lagging or stopped on the take-away table. Improper placement earlier in the chain can consequently result in faulty transfer from the take-away table to the stacking surface and improper nesting within the stack.
With a vertical stop gate system, the system does not decrease the take-away table speed but rather a barrier rotates to form a vertical wall to prevent the pressware products from advancing. While halting the flow of products, the gate can cause physical injury to personnel by trapping or pinching appendages or damage to the products themselves when the wall comes down on top of at least a portion of the product. Damaged products later advanced to a stack can prevent proper stacking, leading to wasted time and/or products. Additionally, the lowered gate can cause product jams on the take-away table once stacking resumes, dislocating the product's proper placement and resulting in a bad stack, as previously mentioned.
There is a need, therefore, for new pressware stacking systems and methods for using same.